Scary steering with weight in the back.

[AnotherWs6]

So with more cold coming and my pellet supply dwindling I decided to take my 68 1/2 ton Suburban to go get more pellets. Normally I take my 2000 Silverado. I buy 40 bags at a time (40 lbs each) and have zero issue getting them home. Truck squats a little, brake pedal lets you know you've got some extra weight but all in all it's totally fine. Well the Silverado was down with a bad transmission at the time so old Suburban it was.

I paid for 10 bags and backed the my truck into the barn. Loaded up the 400lbs worth and took a look at how the truck was sitting. It looked pretty good so I said let me get another 10 bags. So I was at 800lbs. It wasn't squatting badly. The brakes felt fine on the way home and it had plenty of power but the steering, good G the steering!!! It felt like the front wheels were barely on the ground. It was not a fun drive home as I was nervous the whole time.

I bought this truck ultimately to tow a trailer for camping, thinking something under 5,000lbs will be fine. It's getting new power discs all around. But after that trip I'm concerned. 500 lbs worth of tongue weight and a bunch of our crap in the back is going to put me at the same, roughly, 800lbs, with a lot of the weight behind the rear axle. What should I do here? The suspension has been gone through, everything is in good shape, nice and tight front end. Drives great normally. Would helper springs be a good idea? And is the darty steering normal?

[pwdcougar]

How close to the back of the truck did you load? Do you have a second row seat? If you loaded all the way at the back behind a second row seat you have a lot of weight over and behind the rear axle. Never had a problem with my 4WD Burb. Had it so over loaded with firewood once that the rear springs were compressed tight against the rubber stoppers.

Paul

[56HOTRODDER]

i would look at alignment or play in the box itself. Last week i had 400+ hard bricks in mine plus assorted junk (1500-2000lbs ) and had the springs pretty squated but other than a longer stopping distance I had no problems. My front end has had benign neglect for 108000 miles and is by no means fresh. I would not say your situation is typical.

[AnotherWs6]

Originally Posted by 56HOTRODDER

i would look at alignment or play in the box itself. Last week i had 400+ hard bricks in mine plus assorted junk (1500-2000lbs ) and had the springs pretty squated but other than a longer stopping distance I had no problems. My front end has had benign neglect for 108000 miles and is by no means fresh. I would not say your situation is typical.

I hear you, but the front end is tight in general. I often daily drive this thing to work on mediocre 75MPH highways with no issue. It's the weight in the back that threw things off. Could the alignment be off? maaaaybe. But not by much given its normal behavior. There isn't really any play in the box that I noticed either.

I'm trying to determine what is normal vs what needs to be addressed. Again, the new pickup that I've been driving for 15 plus years handles things fine. Is there something wrong with my truck? Is that just what happens? I want to know if I have an issue or just have an old truck. The truck is very tight in general.

[HO455]

What kind of tires do you have on it? Front and rear?

[Warrens69GMC]

I think its just the loading. When i have more than say 400 lbs, I spread it through the vechicle. I will put some in the second seat and if need be (more weight) then I will put some in the passenger compartment.

I carried 20 cases of oil (quarts) through the mountains and 78 miles at 55-80mph in a volkswagen jetta. Ran like it wasn't loaded.

[67 Burb]

Originally Posted by HO455

What kind of tires do you have on it? Front and rear?

Was just thinking the same thing. These came from the factory with skinny 8.15 X 15 tires. When I had 275/70R15 tires on my Burb, if the road was a bit slippery it felt like the truck was out of control.

[AnotherWs6]

It's on factory 15 inch rims. Goodyear Wranglers. Fairly new. A very tame, street oriented version of them. I believe they are 225's, may be 225/70???

I will say that the weight was biased towards the rear and I could have done a better job of getting some of it forward. But 500lbs worth of tongue weight is going to be about the same.

[AnotherWs6]

There were helper springs available from the factory, no? Are those still being produced by anyone?

[Bigdav160]

I had a '72 Pickup equipped with G60 overload springs. I towed a boat frequently with the truck. (2 times a week). I thought they worked so well I bought a set for my coil sprung Suburban. Sold the Suburban before I got to put them on.

[AnotherWs6]

So it's like half of a leaf spring that bolts to the frame and axle?

[Bigdav160]

Yes, the pad has a rubber cushion and fits between the axle and trailing arm.

The spring has no effect on ride quality until there's enough weight in the back. Then it stiffens up.

[HO455]

I see that you said the suspension was gone through but I would take a good look at that. I believe your tires are rated for the load you had so assuming there are no unseen defects in the tires and they are inflated properly the problem is in the suspension. You could of suffered an early failure of a new part. I had an idler arm fail on my S10 with just under 10 thousand miles on it. Or something is loose and moving around under load. I've taken vehicles with odd driving problems to my local chain tire store and have them look at the problem. They usually will look at it and come back with a whole list of stuff and then I check the items out myself. Sometimes an independent set of eyes will see what I miss. These trucks were built to handle loads that today's base F150 would crumble under. So the truth is out there, underneath that Burban.

[AnotherWs6]

Where can I find a set of these overload springs? I've seen guys running air bags inside the coil spring. Not sure which is best. Overload seems more simple and doesnt really require maintenance.

[68c10airstream]

Anotherws6, if the rear on your suburban is coils look for moog cargo coils if you want a normal stock ride height. They work on the principle of normally you ride on wider spaced coils that are softer, and when weight gets added you compress these loose coils and then start to compress tighter wound coils, hence variable rate.

If you worry about the rear dragging when you pull a trailer use leveling bars (bars are matched to the load). Going camping it never fails to see a trailer sitting weird hooked up to a truck. I believe (without looking it up) the top of the trailer ball to the ground is supposed to be about 20", that's why there are various step tongues to achieve this height.

[67 Burb]

My Burb came from the factory with the 04C60AB auxiliary springs option, but a previous owner removed them to install a hidden hitch. Duh? What was he thinking???? Now I have a class III hitch with no tongue weight capacity.

[AnotherWs6]

I get the idea pf progressive rates, had them on a fox body mustang years ago. Handled great but didn't ride harsh.

My truck came with heavy duty coils and wasn't sagging much. Maybe it needs an alignment while there is some weight in the back. Does that make any sense?